serial: fix warning when driver doesn't support closing_wait (bgo #630670)

It appears that GIOChannel might also do some flushing, so make sure
our warning captures that delay if there is one.  Also be paranoid
and make sure nothing reset our closing_wait value.

1 files changed, 15 insertions, 3 deletions

diff --git a/src/mm-serial-port.c b/src/mm-serial-port.c
index 568f4e4a..ce2dfebd 100644
--- a/src/mm-serial-port.c
+++ b/src/mm-serial-port.c
@@ -902,7 +902,7 @@ mm_serial_port_open (MMSerialPort *self, GError **error)
 
     /* Don't wait for pending data when closing the port; this can cause some
      * stupid devices that don't respond to URBs on a particular port to hang
-     * for 30 seconds when probin fails.
+     * for 30 seconds when probing fails.  See GNOME bug #630670.
      */
     if (ioctl (priv->fd, TIOCGSERIAL, &sinfo) == 0) {
         sinfo.closing_wait = ASYNC_CLOSING_WAIT_NONE;
@@ -980,11 +980,25 @@ mm_serial_port_close (MMSerialPort *self)
 
     if (priv->fd >= 0) {
         GTimeVal tv_start, tv_end;
+        struct serial_struct sinfo;
 
         mm_info ("(%s) closing serial port...", device);
 
         mm_port_set_connected (MM_PORT (self), FALSE);
 
+        /* Paranoid: ensure our closing_wait value is still set so we ignore
+         * pending data when closing the port.  See GNOME bug #630670.
+         */
+        if (ioctl (priv->fd, TIOCGSERIAL, &sinfo) == 0) {
+            if (sinfo.closing_wait != ASYNC_CLOSING_WAIT_NONE) {
+                mm_warn ("(%s): serial port closing_wait was reset!", device);
+                sinfo.closing_wait = ASYNC_CLOSING_WAIT_NONE;
+                (void) ioctl (priv->fd, TIOCSSERIAL, &sinfo);
+            }
+        }
+
+        g_get_current_time (&tv_start);
+
         if (priv->channel) {
             g_source_remove (priv->watch_id);
             priv->watch_id = 0;
@@ -993,8 +1007,6 @@ mm_serial_port_close (MMSerialPort *self)
             priv->channel = NULL;
         }
 
-        g_get_current_time (&tv_start);
-
         tcsetattr (priv->fd, TCSANOW, &priv->old_t);
         tcflush (priv->fd, TCIOFLUSH);
         close (priv->fd);